The costs of the works shall be deemed to include all the costs of acquisition or construction of the works, the costs of all property, rights, easements, and franchises deemed necessary or convenient for the works, and for the improvements determined upon as provided in §7-35-420; interest upon bonds prior to and during construction or acquisition and for six (6) months after the completion of construction or acquisition of the improvements; engineering and legal expenses; expense for estimates of cost and of revenues; expense for plans, specifications and surveys; other expenses incident or necessary to determining the feasibility or practicability of the enterprise; administrative expense; and such other expenses as may be necessary to the financing authorized in this part and the construction or acquisition of the works and the placing of the works in operation and the performance of the things required in this part or permitted in connection with any of the provisions of this part.